Orion TV4200HD - No power.

[gpatel_uk]

Why did you think those capacitors were faulty?

Do you have pictures?

When I tested them using my digital multimeter on the ohms setting they showed an open circuit as though nothing was in between the probes. Everything else on the board gave me a reading. Did i do it wrong? As you can see I'm not an expert hahaha. Hence me asking so many questions

I'll get pictures tomorrow. *photos now added

 

[gpatel_uk]

I'm not sure what's going on as I've just tested the ic's again on the buffer boards. This time the lower board ic's are fine. It is the 6 ic's on the upper buffer board. I set my multimeter in 'diode' setting as shown on a YouTube video. Lower board gave me readings through out. Upper gave me very infrequent readings. I've already ordered 12 so looks like I have 6 spare now hahaha!!! But not to worry as its a learning curve for me and luckily not too expensive.

 

[davenn]

When I tested them using my digital multimeter on the ohms setting they showed an open circuit as though nothing was in between the probes. Everything else on the board gave me a reading. Did i do it wrong? As you can see I'm not an expert hahaha. Hence me asking so many questions

I'll get pictures tomorrow. *photos now added

capacitors will show open connection there is NO physical internal connection

Dave

 

[gpatel_uk]

If I put a small current through the capacitor, what reading should I get?
I get a voltage reading getting lower and lower. Is that good or bad?
Thanks.

 

[gpatel_uk]

capacitors will show open connection there is NO physical internal connection

Dave

Is it worth getting one of these?

http://proto-pic.co.uk/capacitance-meter-diy-kit/

 

[davenn]

Is it worth getting one of these?

http://proto-pic.co.uk/capacitance-meter-diy-kit/

looks a good kit

will give you some worthwhile building experience
just check around before buying that one and see if there are any that go higher than 500uF say up to 1000 or 10000uf.
but for most general capacitor checking it should do you well

Dave

 

[davenn]

If I put a small current through the capacitor, what reading should I get?
I get a voltage reading getting lower and lower. Is that good or bad?
Thanks.

current DOESNT flow through a capacitor, see my post previous to this comment of yours

cheers
Dave

 

[gpatel_uk]

current DOESNT flow through a capacitor, see my post previous to this comment of yours

cheers
Dave

Maybe I'm typing the wrong words to explain what I'm trying to ask. I looked around and found this,

'When you apply a D.C Voltage in parallel with capacitor , a potential difference is applied across the plates of the capacitor, due to this potential difference , the electron start moving towards hgher potential, this is how the current starts flowing throught the capacitor. Whenever you think about current , think about the movement of electrons.

Further, as current through starts increasing , the electric field developed which stops further accumulation of electrons. Therefore the current keeps on decreasing in the circuit while charge resting on the plates starts increasing . The charge accumulation increases exponentially and attains an equilibrium situation at infinity time.'

Anyhow it doesn't really point me in the right direction. But I think I understand now. The only way to test a capacitor is to use a capacitor tester/meter.

My last few questions. Do you always have to take out the capacitors out of the circuit or can you test while it is in?

And last, how would you test a capacitor?

Thanks

 

[davenn]

Maybe I'm typing the wrong words to explain what I'm trying to ask. I looked around and found this, 'When you apply a D.C Voltage in parallel with capacitor , a potential difference is applied across the plates of the capacitor, due to this potential difference , the electron start moving towards hgher potential, this is how the current starts flowing throught the capacitor. Whenever you think about current , think about the movement of electrons.

You get a build up of positive and negative charges on the respective plates of the cap
Current is still NOT flowing THROUGH the cap.

Further, as current through starts increasing , the electric field developed which stops further accumulation of electrons. Therefore the current keeps on decreasing in the circuit while charge resting on the plates starts increasing . The charge accumulation increases exponentially and attains an equilibrium situation at infinity time.'

Anyhow it doesn't really point me in the right direction. But I think I understand now. The only way to test a capacitor is to use a capacitor tester/meter.
My last few questions. Do you always have to take out the capacitors out of the circuit or can you test while it is in?
And last, how would you test a capacitor?
Thanks

it is preferable to remove the cap from circuit so that other components dont affect the reading, in general the same applies to resistors and semi's ---diodes and transistors

Personally, I use a capacitance meter, it gives me a believable value taking the tolerance of the cap and the meter into account

Dave